JP2002110582A - Semiconductor substrate heat treatment equipment - Google Patents

Abstract

[PROBLEMS] To provide a semiconductor substrate heat treatment apparatus that realizes highly accurate temperature measurement. A halogen lamp (14) for heating a mounted semiconductor substrate (3) for heat treatment, and a halogen lamp (1).
A radiation thermometer 11 for measuring the temperature of the semiconductor substrate 3 by taking in the quartz rod 7 light emitted from the semiconductor substrate 3 heated by the light from 4. A semiconductor substrate heat treatment apparatus characterized by having a cavity 17 which is provided around and which absorbs light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate heat treatment apparatus for heat treating a semiconductor substrate.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing the configuration of a rapid thermal process (Rapid Thermal Process) apparatus used as a CVD apparatus or an annealing apparatus for manufacturing a semiconductor integrated circuit. As shown in FIG. 1, the rapid heat treatment apparatus includes a heating source 1 including a halogen lamp, a guard ring 5 for supporting a wafer 3 to be subjected to a heat treatment, and a quartz rod 7 attached to a bottom plate 8. And an optical fiber 9 for transmitting light emitted from the wafer 3 detected by the quartz rod 7, and a radiation thermometer 11 connected to the optical fiber.

The rapid heat treatment apparatus having the above-described structure heats the mounted wafer 3 from room temperature to, for example, 1000.degree. C. at a speed of, for example, 100.degree. C./sec by radiation light from the halogen lamp.

Further, the radiation thermometer 11
Light emitted from the quartz rod 7 is detected by the quartz rod 7, and the temperature of the wafer 3 is detected according to the detected light.

However, in the rapid heat treatment apparatus having the above-described configuration, the temperature of the wafer 3 is measured in accordance with the light detected by the quartz rod 7, and therefore, as shown in FIG. When the stray light 10 consisting of a part of the light emitted from the quartz rod 7 is reflected multiple times between the wafer 3 and the bottom plate 8 and is incident on the quartz rod 7, the light other than the light emitted from the wafer 3 is also detected. Therefore, there is a problem that the temperature of the wafer 3 cannot be measured accurately.

[0006] In the above-mentioned stray light, the range in which multiple reflection occurs is uncertain, so that an accurate emissivity correction formula cannot be created.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a heat treatment apparatus which realizes highly accurate temperature measurement.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor substrate heat treatment apparatus for heat treating a semiconductor substrate, wherein the heating means heats the semiconductor substrate by irradiating light to one surface of the semiconductor substrate; A reflection plate disposed opposite to the semiconductor substrate so as to form a reflection cavity with the other surface of the substrate, and capturing light radiated from the semiconductor substrate provided on the reflection plate and heated by the heating means. Temperature measuring means for measuring the temperature of the semiconductor substrate by
A light absorbing unit that is provided around the temperature measuring unit and absorbs irregularly reflected light generated in the reflective cavity, or a light reflection suppressing unit that suppresses reflection of irregularly reflected light generated in the reflective cavity. This is achieved by providing a semiconductor substrate heat treatment apparatus. According to such a means, the diffusely reflected light (stray light) incident on the temperature measuring means is absorbed in advance by the light absorbing means, or the reflection of the diffusely reflected light (stray light) is suppressed by the light reflection suppressing means. It is possible to prevent the irregularly reflected light from entering the temperature measuring means.

If the light absorbing means is constituted by, for example, a cavity forming a black body, diffusely reflected light can be effectively absorbed. Here, in the cavity, when the radius of the light intake port in the temperature measuring means is r and the numerical aperture in a vacuum is sin θ, r
/ Tanθ, and when the distance from the semiconductor substrate in the cavity is D, the distance from the temperature measuring means is 2n times Dtanθ (n is a natural number). It is desirable to be installed. Furthermore, it is desirable that the opening radius of the cavity be a value equal to or greater than Dtanθ.

The light absorbing means may be formed of a groove having a predetermined opening radius and depth.
By confining the irregularly reflected light in the groove, it is possible to prevent the irregularly reflected light from entering the temperature measuring means.

Further, if the light absorbing means has a closest distance to the semiconductor substrate shorter than the closest distance to the semiconductor substrate in the temperature measuring means and comprises a projecting body having a predetermined groove, It is possible to obtain a semiconductor substrate heat treatment apparatus which can effectively confine diffusely reflected light and is easy to manufacture.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. [First Embodiment] FIG. 2 is a diagram showing a configuration of a rapid heating and heat treatment apparatus according to a first embodiment of the present invention. As shown in FIG. 2, the rapid heating and heat treatment apparatus according to the first embodiment includes a halogen lamp house 13 for adjusting electric power supplied to the halogen lamp 14, a halogen lamp 14, and a chamber 20 for heat-treating the wafer 3. , A radiation thermometer 11. As means for heating the wafer 3, a resistance heating source utilizing heat generated by passing a current to the resistor may be provided instead of the lamp as described above.

The champer 20 supports the wafer 3 and has a guard ring 5 made of SiC, a bearing 15 for rotating the guard ring 5 on which the wafer 3 is mounted, a bottom plate 8, and a bottom plate 8.
A quartz rod 7 for detecting light emitted from the wafer 3, a water cooling unit 19 for cooling the bottom plate 8, and a cavity 1 embedded in the bottom plate 8.
7 is included. The quartz rod 7 is connected to a radiation thermometer 11
And the interior of the chamber 20 is evacuated.

As described above, in the rapid heating and heat treatment apparatus according to the first embodiment of the present invention, the cavity 17 is provided around the quartz rod 7, and the multiplex is formed between the wafer 3 and the bottom plate 8 from any gap. The stray light 10 that enters the quartz rod 7 while being reflected is absorbed. That is, in order to accurately measure the temperature of the wafer 3, the quartz rod 7
It is desirable that only the light emitted from the wafer 3 be incident on the substrate as described above. Therefore, the cavity 1 as described above
7, the stray light 10 caused by the light emitted from the halogen lamp 14 is absorbed by the wafer 3.
Temperature measurement accuracy can be improved.

In the rapid heating and heat treatment apparatus having the above-described configuration, the halogen lamp house 13 switches the halogen lamp 1 according to the measured temperature of the wafer 3.
In order to adjust the power supplied to the wafer 4 and control the degree of heating of the wafer 3, the accuracy of the temperature measurement for the wafer 3 is improved as described above, thereby improving the accuracy of the temperature of the heat treatment in the rapid heating heat treatment apparatus. Can be done.

Hereinafter, the cavity 17 will be described in more detail. FIG. 3 is a diagram showing the configuration of the cavity 17 shown in FIG. As shown in FIG. 3, the inner curved surface 18a of the cavity 17 is subjected to black hard alumite treatment, and the groove surface 18b is subjected to polishing treatment. In addition, the bottom plate 8
Surface 21 is polished.

In FIG. 3, r indicates the radius of the quartz rod 7, θ is the critical angle of the quartz rod 7 (the numerical aperture of the quartz rod 7 is sin θ), D is the distance between the wafer 3 and the bottom plate 8, and R is Represents the center-to-center distance between the quartz rod 7 and the cavity 17, and L represents the width (opening width) of the opening of the cavity 17.

The cavity 17 as described above may be scattered around the quartz rod 7 as shown in FIG. 4, or may have a cross section having a shape as shown in FIGS. And
As shown in FIG. 5, a donut-shaped one surrounding the quartz rod 7 may be used.

In the above, in order to effectively absorb the stray light 10, first, the distance D is set to a value equal to or smaller than r / tan θ obtained by the radius r of the quartz rod 7 and the above θ. Then, R is a natural number times r ′ shown in FIG. 3, that is, n · r ′ (= n · D) when n is a natural number.
Tan θ). Note that R is a value larger than (r + L / 2). And furthermore,
L is a value equal to or greater than 2D tan θ.

Further, if L is set to a value larger than 2D tan θ in the above, stray light 10 entering by multiple reflection can be absorbed into the cavity 17 regardless of the value of R. When L is a value of 2D tan θ, it is most effective that R is a value obtained from nD tan θ as described above. Here, as n is smaller, that is, as the cavity 17 is disposed closer to the quartz rod 7, the accuracy of temperature measurement by lighting the quartz rod 7 can be increased.

As described above, according to the rapid heating and heat treatment apparatus according to the first embodiment of the present invention, stray light as a kind of noise incident on the quartz rod 7 is absorbed by the cavity 17 before incidence, so that radiation The accuracy of the temperature measurement by the thermometer 11 can be improved. [Second Embodiment] FIG. 6 is a diagram showing a configuration of a rapid heating and heat treatment apparatus according to a second embodiment of the present invention. As shown in FIG. 6, the rapid heating heat treatment apparatus according to the second embodiment includes a heating source 1 including a lamp or a resistor, and a wafer 3, similarly to the rapid heating heat treatment apparatus according to the first embodiment. Guard ring 5 to be supported and bottom plate 12
And a quartz rod 7 provided on the bottom plate 12;
A radiation thermometer 11 and an optical fiber 9 connecting the quartz rod 7 and the radiation thermometer 11 are provided.

In the rapid heat treatment apparatus according to the second embodiment, a groove 22 having a predetermined opening width and depth is formed around the quartz rod 7 in the bottom plate 12.
Is formed. Here, the opening width and position of the groove 22 are determined in the same manner as the cavity 17 in the first embodiment.

That is, when the opening width of the groove 22 is set to a value larger than 2D tan θ in FIG. 3, the stray light 10 that enters by the multiple reflection regardless of the position where the groove 22 is formed.
Can be confined in the groove 22. When the opening width is set to the value of 2D tan θ, it is most effective to form the groove 22 at a position separated from the quartz rod 7 by nD tan θ. Here, as n is smaller, that is, as the groove 22 is formed at a position closer to the quartz rod 7, the accuracy of temperature measurement by lighting the quartz rod 7 can be improved. Can be reliably confined.

In place of the groove 22, FIG.
May be provided. Here, the recess 23
Is composed of a cavity having an inner curved surface 18a subjected to black alumite treatment, and an aluminum reflector 27 for increasing the reflectance at the upper part of the cavity, and stray light guided to the cavity is effectively absorbed. .

In place of the groove 22, a V-shaped groove 29 shown in FIG. 7 may be formed in the bottom plate. The groove 22 and the groove 29 described above have an advantage that processing is easy. [Embodiment 3] FIG. 8 is a diagram showing a configuration of a rapid heating and heat treatment apparatus according to Embodiment 3 of the present invention. As shown in FIG. 8, the rapid heating heat treatment apparatus according to the third embodiment has the same configuration as the rapid heating heat treatment apparatus according to the second embodiment shown in FIG. The bank-shaped protruding body 31 on which the quartz rod 7 is formed
Is provided in the vicinity of the. here,
As shown in FIG. 8, the closest distance between the protrusion 31 and the wafer 3 is D1, the guard ring 5 and the bottom plate 30 are different.
Assuming that the closest distance to D2 is D2, D1 is a value smaller than D2.

According to the above configuration, by providing the protruding body 31, the distance D shown in FIG. 3 can be substantially reduced, so that the width L of the opening calculated by 2D tan θ is obtained. Can be set to a smaller value. Therefore, as shown in FIG. 8, by forming the groove 32 having a width not less than the lower limit in the protruding body 31, the same effect as the cavity 17 according to the first embodiment shown in FIG. Can be obtained. It is to be noted that the greater the depth of the groove 32 is, the more effective the confinement of the stray light 10 is, as in the case of the groove 22. In addition, the projecting body 31 having the above structure is effective not only in the vicinity of the quartz rod 7 but also in the lower part of the guard ring 5.

As described above, the rapid heating and heat treatment apparatus according to the third embodiment in which the projecting body 31 having the groove 32 is formed,
Although the same effects as those of the rapid heating and heat treatment apparatus according to the first and second embodiments are obtained, the protruding body 31 is more easily formed on the bottom plate 30 than the cavity 17 shown in FIG. There are benefits.

As described above, according to the semiconductor substrate heat treatment apparatus of the present invention, irregularly reflected light incident on the temperature measuring means is absorbed by the light absorbing means in advance, or the reflection of the irregularly reflected light is suppressed. Accordingly, it is possible to prevent the irregularly reflected light from being incident on the temperature measuring means, to increase the accuracy of the temperature measurement on the semiconductor substrate by the temperature measuring means, and to execute the heat treatment on the semiconductor substrate with high temperature accuracy.

If the light absorbing means is formed of, for example, a cavity forming a black body, diffusely reflected light can be effectively absorbed. Further, the light absorbing means may be formed of a groove having a predetermined opening radius and depth, so that the irregularly reflected light is prevented from entering the temperature measuring means by confining the irregularly reflected light in the groove. Therefore, the accuracy of the temperature measurement by the temperature measuring means can be improved, and a highly accurate heat treatment can be performed on the semiconductor substrate.

Further, if the light absorbing means has a closest distance to the semiconductor substrate shorter than the closest distance to the semiconductor substrate in the temperature measuring means and comprises a projecting body having a predetermined groove, Since the irregularly reflected light can be effectively confined and a semiconductor substrate heat treatment apparatus that can be easily manufactured can be obtained, the manufacturing cost can be further reduced.

[Brief description of the drawings]

FIG. 1 shows a conventional rapid thermal process.
s) It is a figure which shows the structure of a device.

FIG. 2 is a diagram showing a configuration of a rapid heating and heat treatment apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a configuration of a cavity shown in FIG. 2;

FIG. 4 is a first plan view showing the arrangement of the cavity shown in FIG. 2;

FIG. 5 is a second plan view showing the arrangement of the cavity shown in FIG. 2;

FIG. 6 is a diagram showing a configuration of a rapid heating heat treatment apparatus according to a second embodiment of the present invention.

FIG. 7 is a diagram showing another configuration example of the groove shown in FIG. 6;

FIG. 8 is a diagram showing a configuration of a rapid heating and heat treatment apparatus according to Embodiment 3 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat source 3 Wafer 5 Guard ring 7 Quartz rod 8, 12, 30 Bottom plate 9 Optical fiber 10 Stray light 11 Radiation thermometer 13 Halogen lamp house 14 Halogen lamp 15 Bearing 17 Cavity 18a Inner curved surface 18b Groove surface 19 Water cooling unit 20 Chamber 21 surface 22, 29, 32 groove 23 concave portion 27 aluminum 31 projecting body

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ken Sakuma 1-2-41 Machiya, Shiroyamacho, Tsukui-gun, Kanagawa Prefecture F-term in Tokyo Electron Yamanashi Co., Ltd. (reference) 3K058 AA42 BA00 CA05 CA12 CA17 CA23 CA46 CA70 CA93 CB09 CB10 CB26 CE02 CE12 CE17 EA13 4K030 CA04 FA10 JA03 KA24 KA39 LA15 5F045 BB08 DP04 EB02 EK12 EM02 EM09 GB05

Claims (8)

[Claims] 1. A semiconductor substrate heat treatment apparatus for heat treating a semiconductor substrate, comprising: heating means for irradiating one surface of the semiconductor substrate with light to heat the semiconductor substrate; A reflection plate disposed opposite to the semiconductor substrate so as to form a reflection cavity therebetween, and provided on the reflection plate, by taking in light emitted from the semiconductor substrate heated by the heating means. A semiconductor substrate heat treatment, comprising: a temperature measuring means for measuring a temperature of a semiconductor substrate; and a light absorbing means provided around the temperature measuring means and absorbing irregularly reflected light generated in the reflection cavity. apparatus. 2. A semiconductor substrate heat treatment apparatus for heat-treating a semiconductor substrate, comprising: heating means for irradiating one surface of the semiconductor substrate with light to heat the semiconductor substrate; A reflection plate disposed opposite to the semiconductor substrate so as to form a reflection cavity therebetween, and provided on the reflection plate, by taking in light emitted from the semiconductor substrate heated by the heating means. Temperature measuring means for measuring the temperature of the semiconductor substrate; and light reflection suppressing means provided around the temperature measuring means and suppressing reflection of irregularly reflected light generated in the reflection cavity. Semiconductor substrate heat treatment equipment. 3. The semiconductor substrate heat treatment apparatus according to claim 1, wherein said light absorbing means comprises a cavity forming a black body. 4. The opening radius of the cavity is defined as sin θ, the numerical aperture in a vacuum when the temperature measuring means captures the light, and D as the distance of the cavity from the semiconductor substrate. 4. The semiconductor substrate heat treatment apparatus according to claim 3, wherein the value is not less than Dtan θ. 5. The method according to claim 5, wherein a numerical aperture in a vacuum when the temperature measuring unit captures the light is sin θ, and a distance between the cavity and the semiconductor substrate is D. The semiconductor substrate heat treatment apparatus according to claim 3, wherein the semiconductor substrate heat treatment apparatus is disposed at a distance of 2n times Dtan θ (n is a natural number) from the means. 6. The cavity according to claim 1, wherein a numerical aperture in a vacuum when the temperature measuring means takes in the light is sin θ, and a radius of the light taking-in port in the temperature measuring means is r. 4. The apparatus for heat treating a semiconductor substrate according to claim 3, wherein the apparatus is disposed at a position separated from the semiconductor substrate by a distance of r / tan [theta] or less. 7. The semiconductor substrate heat treatment apparatus according to claim 1, wherein said light absorbing means comprises a groove having a predetermined opening radius and a predetermined depth. 8. The light absorbing means comprises a projecting body having a closest distance to the semiconductor substrate shorter than the closest distance to the semiconductor substrate in the temperature measuring means and having a predetermined groove. 3. The semiconductor substrate heat treatment apparatus according to item 1.